source/camera.cpp

   1 #include <cmath>
   2 #include "camera.h"
   3 #include "matrix.h"
   4
   5 namespace Msp {
   6 namespace GL {
   7
   8 Camera::Camera():
   9         fov(Geometry::Angle<float>::from_turns(0.125)),
  10         height(0),
  11         aspect(4.0/3.0),
  12         clip_near(0.1),
  13         clip_far(10),
  14         frustum_x(0),
  15         frustum_y(0),
  16         position(0, 0, 0),
  17         look_dir(0, 0, -1),
  18         up_dir(0, 1, 0)
  19 {
  20         update_projection_matrix();
  21         update_object_matrix();
  22 }
  23
  24 void Camera::set_field_of_view(const Geometry::Angle<float> &f)
  25 {
  26         fov = f;
  27         update_projection_matrix();
  28 }
  29
  30 void Camera::set_orthographic(float w, float h)
  31 {
  32         fov = Geometry::Angle<float>::zero();
  33         height = h;
  34         if(w)
  35                 aspect = w/h;
  36         update_projection_matrix();
  37 }
  38
  39 void Camera::set_aspect_ratio(float a)
  40 {
  41         aspect = a;
  42         update_projection_matrix();
  43 }
  44
  45 void Camera::set_depth_clip(float n, float f)
  46 {
  47         clip_near = n;
  48         clip_far = f;
  49         update_projection_matrix();
  50 }
  51
  52 void Camera::set_frustum_axis(float x, float y)
  53 {
  54         frustum_x = x;
  55         frustum_y = y;
  56         update_projection_matrix();
  57 }
  58
  59 void Camera::set_frustum_rotation(const Geometry::Angle<float> &r)
  60 {
  61         rotate = r;
  62         update_projection_matrix();
  63 }
  64
  65 void Camera::set_position(const Vector3 &p)
  66 {
  67         position = p;
  68         update_object_matrix();
  69 }
  70
  71 void Camera::set_look_direction(const Vector3 &l)
  72 {
  73         look_dir = normalize(l);
  74         update_object_matrix();
  75 }
  76
  77 void Camera::look_at(const Vector3 &p)
  78 {
  79         set_look_direction(p-position);
  80 }
  81
  82 void Camera::set_up_direction(const Vector3 &u)
  83 {
  84         up_dir = normalize(u);
  85         update_object_matrix();
  86 }
  87
  88 void Camera::set_object_matrix(const Matrix &m)
  89 {
  90         position = m.column(3).slice<3>(0);
  91         look_dir = normalize(-m.column(2).slice<3>(0));
  92         up_dir = normalize(m.column(1).slice<3>(0));
  93         update_object_matrix();
  94 }
  95
  96 Vector3 Camera::project(const Vector4 &p) const
  97 {
  98         Vector4 r = proj_matrix*(view_matrix*p);
  99         return r.slice<3>(0)/r.w;
 100 }
 101
 102 Vector3 Camera::project(const Vector3 &p) const
 103 {
 104         return project(Vector4(p.x, p.y, p.z, 1.0));
 105 }
 106
 107 Vector4 Camera::unproject(const Vector4 &p) const
 108 {
 109         Vector4 r = invert(proj_matrix)*Vector4(p.x, p.y, p.z, 1.0f);
 110         r = matrix*Vector4(r.x/r.w, r.y/r.w, r.z/r.w, p.w);
 111         return r;
 112 }
 113
 114 Vector3 Camera::unproject(const Vector3 &p) const
 115 {
 116         return unproject(Vector4(p.x, p.y, p.z, 1.0f)).slice<3>(0);
 117 }
 118
 119 void Camera::apply() const
 120 {
 121         MatrixStack::projection() = proj_matrix;
 122         MatrixStack::modelview() = view_matrix;
 123 }
 124
 125 void Camera::update_projection_matrix()
 126 {
 127         float frustum_h = (fov!=Geometry::Angle<float>::zero() ? tan(fov/2.0f)*clip_near : height/2);
 128         float frustum_w = frustum_h*aspect;
 129         float left = frustum_w*(frustum_x-1.0f);
 130         float right = frustum_w*(frustum_x+1.0f);
 131         float bottom = frustum_h*(frustum_y-1.0f);
 132         float top = frustum_h*(frustum_y+1.0f);
 133         if(fov>Geometry::Angle<float>::zero())
 134                 proj_matrix = Matrix::frustum(left, right, bottom, top, clip_near, clip_far);
 135         else
 136                 proj_matrix = Matrix::ortho(left, right, bottom, top, clip_near, clip_far);
 137         proj_matrix = Matrix::rotation(rotate, Vector3(0, 0, 1))*proj_matrix;
 138 }
 139
 140 void Camera::update_object_matrix()
 141 {
 142         Vector3 right_dir = normalize(cross(look_dir, up_dir));
 143         Vector4 columns[4];
 144         columns[0] = compose(right_dir, 0.0f);
 145         columns[1] = compose(cross(right_dir, look_dir), 0.0f);
 146         columns[2] = compose(-look_dir, 0.0f);
 147         columns[3] = compose(position, 1.0f);
 148         matrix = Matrix::from_columns(columns);
 149         view_matrix = invert(matrix);
 150 }
 151
 152
 153 Camera::Loader::Loader(Camera &c):
 154         DataFile::ObjectLoader<Camera>(c)
 155 {
 156         add("aspect_ratio", &Loader::aspect_ratio);
 157         add("depth_clip", &Loader::depth_clip);
 158         add("field_of_view", &Loader::field_of_view);
 159         add("look_at", &Loader::look_at);
 160         add("look_direction", &Loader::look_direction);
 161         add("orthographic", &Loader::orthographic);
 162         add("position", &Loader::position);
 163         add("up_direction", &Loader::up_direction);
 164 }
 165
 166 void Camera::Loader::aspect_ratio(float a)
 167 {
 168         obj.set_aspect_ratio(a);
 169 }
 170
 171 void Camera::Loader::depth_clip(float n, float f)
 172 {
 173         obj.set_depth_clip(n, f);
 174 }
 175
 176 void Camera::Loader::field_of_view(float a)
 177 {
 178         obj.set_field_of_view(Geometry::Angle<float>::from_degrees(a));
 179 }
 180
 181 void Camera::Loader::look_at(float x, float y, float z)
 182 {
 183         obj.look_at(Vector3(x, y, z));
 184 }
 185
 186 void Camera::Loader::look_direction(float x, float y, float z)
 187 {
 188         obj.set_look_direction(Vector3(x, y, z));
 189 }
 190
 191 void Camera::Loader::orthographic(float w, float h)
 192 {
 193         obj.set_orthographic(w, h);
 194 }
 195
 196 void Camera::Loader::position(float x, float y, float z)
 197 {
 198         obj.set_position(Vector3(x, y, z));
 199 }
 200
 201 void Camera::Loader::up_direction(float x, float y, float z)
 202 {
 203         obj.set_up_direction(Vector3(x, y, z));
 204 }
 205
 206 } // namespace GL
 207 } // namespace Msp